Resonant Coupling Irises for the Design of New Planar Bandstop Filters

Original planar bandstop filters based on resonant coupling irises have been micromachined on silicon membranes. These filters have been designed for the transmitters (Tx) and the receivers (Rx) of earth terminals in Ka-band satellite communications. Experimental results show that, in addition to an high attenuation (at least 24.5 dB) in the uplink band, the Rx-filter features a very low insertion loss (lower than 0.3 dB over a 1.5 GHz bandwidth) in the downlink band. The filter dimensions have been dramatically reduced and are only 900 μm wide by 2700 μm long.